Grinding machine



Feb. 6, 1934. e. H. KENNEDY I 1,945,904

GRINDING MACHINE Filed Sept. 28, 1932 4 Sheets-Sheet 1 G. H. KENNEDY GRINDING MACHINE Feb. 6, 1934 Filed Sept. 28, 1932 4 sheets-sheei; 2

G. H. KENNEDY GRINDING MACHINE Feb. 6, 1934.

Filed Sept. 28, 1932 4 Sheets-Sheet 4 Patented Feb. 6, 1934 UNITED STATES PATENT OFFlCE GRINDING ll/IACHINE Application September 28, 1932 Serial No. 635,247

9 Claims.

This invention relates to grinding machines, and more particularly to devices of this type which are primarily adapted for the accurate and uniform resurfacing of the cork cots which are applied to the drawing rolls of spinning machines or the like, although the subject of the present invention is not limited to this use but may be employed in various other grinding or abrading operations.

As is well-known in the art, drawing rolls of the type commonly used in this connection are arranged in pairs, one of each pair disposed above the other, the lower ones being positively driven by means of suitable gearing and the upper ones generally being driven by frictional contact with the bottom rolls. The bottom rolls are made of steel and comprise a series of fluted or longitudinally slotted portions so designed to obtain a better grip on the sliver of cotton or other material as it is drawn between the top and bottom rolls.

The top rolls are also of metal and are generally made in short lengths and assembled end to end. Those portions of the top rolls which lie adjacent the fluted portions of the bottom rolls are provided with cylindrical cork covered cots which are adapted to provide elastic surfaces of contact for the cotton fibers passing between the rolls. After continued operation of these drawing rolls, the cork surfaces of the top roll cots become worn by contact with the cotton and the fluted bottom rolls, and it is necessary to periodically grind or bufi these cots in order to resurface them.

It is therefore a more particular object of the present invention to provide a power driven grinding machine which is well adapted to accomplish the resurfacing of these top roll .cots and which, in the preferred embodiment, comprises a rotary and reciprocating abrading wheel, novel means for effecting the movements of the wheel, an improved rotary work holder and associated driving, adjusting, and feeding elements, and a novel supporting frame construction upon which the operative members and the necessary power transmission means are conveniently disposed.

Further objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings in which one embodiment of my invention is illustrated byway of example.

In the drawings:

Figure 1 is a front elevation of a grinding machine embodying the principles of my invention;

Figure 2 is an end elevation of the same;

Figure 3 is a top plan View;

Figure 4 isa view in horizontal cross-section taken on line 4-4 of Fig. 1;

Figure 5 is a vertical cross-sectional view of the upper portion of the machine, taken on line 55 of Fig. 1;

Figure 6 is a detail, horizontal, cross-sectional view through the tail stock of the work holder and taken on line 6--6 of Fig. 2;

Figure 7 is a view in vertical transverse crosssection taken on line 7--7 of Fig. 6;

Figure 8 is a verticalcross-sectional view of a portion of a machine, showing the wheel dresser and its safetystop, and taken on line 88 of Fig. 1; and

Figure 9 is a vertical cross-sectional view of the grinding wheel hub or carrier, taken on line 99 of Fig. 4. g

Referring now to the drawings, it will be seen that my improved grinding machine is mounted upon a supporting frame designated generally by the numeral '10. This frame comprises the A- shaped side members or legs 11, which are held together by means of the rear cross braces 12, the front and rear adjustable tie rods 13 and 14, and the dust box or pan 15. The dust box 15 is-secured between the frame members 11 by means of the bolts 16,'as more clearly shown in Fig. 5 of the drawings. These bridging or tying elements together with the several countershafts and other members to be described later, serve to effect a rigid and substantial frame structure for the purpose desired.

Mounted upon the fiat upper surface 18 of the side frames 11, by means of the bolts 19, are the brackets 20. Each of the brackets 20 are provided with bearing housings 21 within which are positioned the ball bearing assemblies 22. The inner races of these bearings are suitably secured to the grinding wheel spindle 25 which comprises the end shaft sections 26 and 27 and the central hollow shaft 28, threaded together as at 29. A suitably formed rotary abrading member 30 is carried by the hollow shaft 28 and comprises the grinding wheel 31, the hub 32, the retaining lock nut 33, the felt washers 34 and the metal retaining washers 35 which also serve as abutment members for the reversing mechanism which will be described hereinafter. Upon the outer end of the shaft section 26 which forms a part of the 5 main spindle 25 is mounted a pulley 37 which is adapted to be driven from certain transmission mechanism to which later reference will be made.

The brackets 20 are individually adjustable for- Wardly and rearwardly for properly aligning the 110 spindle and grinding element 30, by means of the locking set bolts 38 which are threaded through the upstanding lugs 39 on each of the side frames.

In practice, the grinding or abrading member is adapted to rotate in order to effect the abrading action upon the work and is also designed to reciprocate laterally in alternate directions in order to evenly distribute the grinding action along the work.

The grinding wheel assembly 30 is provided with an internal key or spline 40 which is secured within a slot formed within the hub 32 by means of the set screws 41. This key 40 is adapted to extend through a slot 43 provided in the shaft 28 in order to permit sliding movement of the grinding element 30 along the spindle 25 but to cause the element 30 to be rotated by the spindle. In order to effect the alternate reciprocation, there is provided a screw shaft or worm 45 which is disposed axially of the hollow shaft 28 and is adapted to bear for relative rotation within the spindle shaft sections 26'an'd'27, as at 46 and 17. The shank 48 of the worm shaft 45 which bears within spindle shaft section 2'7 is extended outwardly and upon the projecting end thereof there is mounted the feed pulley 50. The key 40 which carried by the hub 32 of the grinding wheel 31 is provided with the threads 51 which are adapted to mesh with the threads 52 of the feed worm 45.

It will now be readily understood that when the feed worm 45- isrotated at a speed greater than that of the spindle 25, the grinding member 30 will be moved laterally in one direction, and that when the worm 45 is rotated at a speed which is less than that of the spindle 25, the grinding member will be carried in the opposite direction. The rotation of the spindle 25 and the worm shaft 45 is of course in the same direc tion; preferably, in the present embodiment, counter-clockwise when viewed from the right hand end of the apparatus as in the case of Fig. 2 of the drawings. For convenience in obtaining a uniform grinding action the spindle 25 is adapted to be rotated at a constant speed and the speed of the worm 45 is varied so as to alternately run faster and slower than the spindle 25, by means of the differential surfaces 55 and 56 provided on the feed pulley 50. The pulley 50 is adapted to be driven by means of a belt from the transmission mechanism to which reference will be made. The two surfaces 55 and 56 are connected by a tapered surface 57 to enable the belt to be shifted more readily from one driving surface to the other.

For transmitting the driving power to the rotating portions of the apparatus, a countershaft 60 is rotatably mounted in the bearings 59 carried by the lower portions of the side frames 11. Fast and loose pulleys 61 and 62 are mounted upon the shaft 60 and are adapted to be driven from a suitable source of power, and the belt shifter 63 operated by the hand lever 64 pivoted upon the bracket 65, is adapted to start and stop the machine by transferring the belt from the pulley 61 to the pulley 62 and vice versa. A pulley 68 is fixed to the countershaft 60 and is connected to the spindle driving pulley 3'7 by means of a belt 69. At the opposite end of the countershaft 60 there is fixed a pulley '70 which is connected to the feed pulley 50 by means of a belt '72. This belt '72 is trained about. an idler pulley '74, the axle '75 of which is adapted to be adjustably mounted within the slot '76 formed in the side tension thereby, when it is shifted from one or v the other of the surfaces 55 and 57 of the feed pulley 50.

The means for effecting the reversal of the reciprocating movement of the grinding element 30 will'now be described. Slidably mounted in the upper portions of the brackets 20 is the laterally reciprocating shaft which carries a bracket 86 to which a rearwardly projecting pin 8'7 is secured. A belt'shifting lever 90 is pivotally mounted upon an extended portion 91 of one of the brackets 20, as at 92, and is pivotally connected at a point near its upper end with the pin 8'7 by means of a link 93. Near the lower end of the lever 90 there are provided the spaced arms 95 which are adapted to embrace a portion of the belt '72 immediately beneath the pulley 50. It will now be clearly understood that when the rod or shaft 85 is shifted laterally, as for example toward the right in Fig. 1, the belt shifting arms 95 of the lever 90 will move toward the left and transfer the belt from the larger diameter 5'7 of the pulley 50 to the portion of smaller diameter 55. This will effect an increase with the speed of the worm 45 until it is rotating at a faster rate than the spindle 25 and, the threads of the worm 45 being of the right hand, this will cause the grinding member 30 to move toward the left. Conversely, when the worm 45 is rotated more slowly than the spindle 25, the movement of the grinder will be toward the right. Adjustably mounted upon the rod 85 are the depending brackets 9'7 and 98 which are adapted to provide stop abutments for the grinding member 30 at each end of its lateral travel. At the end of its movement toward the right, as viewed in Fig. 1, the washer plate 35 upon the right hand side of the grinding member 30 will strike the lower end of the bracket 98 and will move the rod 85' toward the right and cause the belt to be shifted from the surface 5'7 to the surface 55 of the feed pulley 50 and thus reverse the direction of travel of the grinding wheel.

In order to retain the belt shifting arrange ment in either of its shifted positions, and to give it a definite and positive impetus toward those positions, there is provided a spring pressed snapover device which will now be described. Mounted upon the right hand side frame 11 is the bracket 100 which is provided with a socket 101 within which is disposed a plunger 102 having an arrow-shaped head 103 provided with oppositely inclined flat surfaces. A collar 104 is pinned to the lower end of the plunger 102 which extends through the bottom of the socketed bracket 100, in order to retain the plunger at a definite maximum projection from the socket under the influ ence of the coil spring 105. A cooperating arrow head earn 107 is provided upon the lower end of the belt shifter lever 90, and the oppositely inclined flat surfaces thereof are adapted to con tact with the corresponding surfaces of the plunger cam 103 when the belt is shifted. It will be readily understood that during the first half of the movement of the belt shifter from one side to the other, the plunger 102 will be depressed until the apexes of the cams 103 and 107 coincide. From this point on, the shifting will be accelerated by the camming effect of the plunger 102 under the influence of the spring 105. Furthermore, until the shifting arrangement is again actuated by contact of one of the belts 35 of the grinding element with one of the brackets 98, the belt shifter will be retained in its previously shifted position by the contact of the plunger cam 103 with the shifter cam 107. For the purpose of manually operating the belt shifter, a handle 109 is provided at the upper end of the lever 90.

In order to retain and properly present the work to be abraded to the grinding member 30, there is provided the following mechanism. A pivoted work rest designated generally by the numeral 110 is provided with oppositely extending horizontal trunnions 111 which are pivotally mounted at the upper forward corners of the side frames 11. At the left hand side of the upper portion of the work rest 110 there is secured the head stock 112, as by means or" the bolts 113. A head stock spindle shaft 115 is rotatably mounted within the head stock 112 by means of the ball bearing assemblies 116 which are spaced by means of a sleeve 117. Upon the outer end of the spindle 115 there is provided a pulley 118 which is adapted to be driven by means of the belt 120 from the pulley 119 keyed to the countershaft 6-3). Within a tapered socket 122 formed in the opposite end of the spindle 115 there is wedgingly disposed the tapered shank 123 of the live center 125. The outer end of the live center 125 is socketed and split to provide a spring chuck 126 for the reception of one end of the work, which in the present instance comprises a section of atop roll of a drawing frame, which top roll is provided with the cork cots previously described.

For the purpose of rotatively supporting the opposite end of the work, the chuck 127 is provided which is similar to the live center or chuck 125, except that the shank 128 thereof is preferably cylindrical and is rotatably received within the anti-friction bearing 129 in the socket or housing 130 provided in the end of the tail stock spindle 132. This spindle 132 is slidably received within the bore 134 formed in the tail stock 135. A cam sleeve 136 is secured to the end of the spindle 132 and is provided with a spiral cam surface which is adapted to cooperate with a corresponding spiral surface on the tail stock as at 137 in order to retract the tail stock spindle from the work when it is desired to apply or remove the lat-- ter. ,A spring 131 is disposed within the enlarged portion of the bore 134 for urging the tail stock chuck 12'? toward the work. This spring is adapted to be compressed between the shoulders formed on the spindle 132 and on the interior of the tail stock when the spindle is retracted. An operating handle 139 is provided on the cam sleeve 136.

Ihe tail stock 135 is also adjustable along the ways 1410 formed in the upper surface of the work rest 110. These ways 140 comprise a groove 1 11 in the bottom of which is formed a slot 142. In order to secure the tail stock 135 at any desired adjusted position along the ways 14!). a pin is provided which is slidably received within the tail stock 135, and is provided with a head 14%; at its lower end and a threaded portion 147 at its upper end. The head 146 is adapted to underlie the margins of the slot 142 on the work rest 110, and the hand operated nut 156 is threaded to the upper portion 147 of the pin in order to clamp the tail stock in its adjusted position. From the immediately preceding description it will be understood that the work is rotatively carried bewhich is threaded a feed screw 16o.

ating wheel 152 and handle 163.

tween the head and tail stocks of the work rest and is adapted to be presented to the rotary and reciprocating grinding wheel already described.

The following mechanism is provided for feeding the work toward the wheel to obtain the proper depth of the cut or abrasion. As previously described, the work rest 110 is trunnioned in the side frames 11 at 111, and it will be noted, especially from Fig. 5 of the drawings, that the work 110 is provided with a depending portion or apron 155 through the central lower portion 156 of The inner end 161 of this feed screw is rounded for contact with the front wall of the dust box 15 and upon theouter end of the screw is mounted an oper- Upon rotation of the screw shaft 160 in the proper direction, with the inner end 161 abutting the stationary box 15, it will be readily understood how the work rest 110 may be brought from the dotted line position to the position shown in solid lines in Fig. 5 of the drawings, and the work thus brought into the desired contact with the grinding wheel 31. In order to set the feed arrangement to obtain a definite depth of abrasion on the work and to retain the setting during the operation upon successive pieces of work to grind or resurface them to a uniform depth, there are provided the knurled lock nuts 165 which are set at the proper position upon the threaded shaft 150 and are adapted to be abutted by the depending portion 155 of the work rest apron 155 when the abrading operation is completed.

A grinding wheel dressing means is provided in connection with the present machine and comprises the dresser tool which is adjustably mounted in the tool rest 171 bolted to the upper surface of the work rest as at 172. By the proper adjustment of the tool 170 and the manipulation of the feed screw 169, the dressing tool 170 may be brought into the desired contact with the rotating and reciprocating grinding wheel 31. In order to provide a safety stop for the dressing tool feed, a bracket 175 is secured to the box 15 as at 176. and the upwardly projecting end 177 thereof is threaded for the reception of a set bolt 178 having the manipulating head 179 and secured in position by means of a lock nut 180. The inner end of the set bolt 178 is adapted to contact the face of the rest 110 as at 181. The safety stop thus described thus supplements the stop nuts 165 when the dressing tool is being employed.

As clearly illustrated in Fig. 5 of the drawings, the dust collecting box or pan 15 is disposed beneath the wheel 31 and is adapted to catch the particles of cork or other material resulting from the abrasion of the work, and for efficiently performing this function the rear wall 183 of the box 15 is of a considerably greater height than the front wall and is extended to proximity with the edge of the wheel 31. The slats 184 are also adapted to extend across the top of the box 15 and act as baiiies for preventing the scattering of the abraded material and directing it more accurately into the dust box or pan 15.

It will be readily understood that this invention is not limited to use in connection with the resurfacing of drawing roll cots but may be employed in numerous other abrading processes, and that various changes and modifications may be in the embodiment disclosed without de parting from the scope of the invention as defined in the following claims. 7

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a device of the class described, in combination, a supporting frame, a pair of spaced brackets mounted on said supporting frame for independent forward and rearward adjustment, means for adjusting the position of said brackets and means for securing them in adjusted positions, bearings in said brackets, a slotted hollow shaft the ends of which are rotatively mounted in said bearings, a grinding wheel slidably mounted on said shaft, means for causing said wheel to rotate with said shaft, a threaded shaft mounted within said hollow shaft for rotative relation thereto, means carried by said wheel and engaging the threads of said shaft, a pulley connected to said hollow shaft at one end thereof, a differential pulley connected to said threaded shaft at the opposite end thereof, belts for driving said pulleys, and means for shifting one of said belts from one surface of said differential pulley to the other whereby reversal of the direction of travel of said wheel may be accomplished.

2. In a device of the class described, in combination, a supporting frame, a grinding wheel, driving means for said wheel including a pulley having belt contacting portions of different diameters connected by a tapering portion, a driving pulley and belt operatively connecting said pulleys and means for shifting said belt from one of said portions of said first named pulley to the other, a weighted freely pivoted idler pulley for taking up the slack in said belt when it is shifted from the portion of larger to that of smaller diameter and maintaining the proper tension in said belt, and a second idler pulley about which the belt is trained, the position of which may be positively adjusted in order to regulate the tension in the belt.

3, In a machine of the class described, in combination, a supporting frame, a grinding wheel mounted on said frame for rotary and reciprocatory movements, a slotted hollow shaft for supporting said grinding wheel, a threaded shaft rotatably mounted within said hollow shaft, a member adjustably and removably carried by the hub of said wheel slidable in the slot of said shaft and threaded to said internal shaft, whereby the relative speeds of said shafts determine the direction of reciprocation of said wheel, means for removably attaching said member to the hub of said wheel and regulating the contact of said member with said threaded shaft, a pulley on one end of said internal threaded shaft having two belt contacting surfaces, and means for reversing the direction of reciprocation of said wheel, including a belt shifter comprising a reciprocating rod having lugs thereon adapted to be actuated by said wheel during its reciprocating movements, a lever pivotally mounted intermediate its length upon the supporting frame, a belt contacting portion near the lower end of said lever, and an operative connection near the upper portion of said lever with said reciprocating rod.

4.. In a grinding machine of the class de scribed, in combination, a supporting frame, a grinding wheel, driving means for said grinding wheel including pulleys and a belt, and controlling means for said wheel, said controlling means including a belt shifter comprising a lever pivoted intermediate its length, means on said lever for contacting said belt, means operatively associated with said wheel for actuating said shifter, a connection between said last named means and said lever, and means associated with said lever for giving said belt an immediate and positive impetus toward its shiftedposition at a certain point during the movement of said belt shifter in either direction, and for retaining said belt and belt shifter in shifted position until again actuated by said .wheel associated means.

5. In a grinding machine of the class described, in combination, a supporting frame, a grinding wheel, driving means for said grinding wheel, including pulleys and a belt, and controlling means for said wheel, said controlling means including a belt shifter comprising a lever pivoted intermediate its length, means on said lever for contacting said belt, means operatively associated with said wheel for actuating said shifter, a connection between said last named means and said lever, and a V-shaped cam mounted on said lever and a cooperating V-shaped spring pressed cam mounted on said frame for giving said belt an immediate and positive impetus toward its shifted position at a certain point during the movement of said belt shifter in either direction, and for retaining said belt and belt shifter in shifted position until again actuated by said wheel associated means. 7

6. In a device of the class described including a stationary frame, and transmission mechanism including pulleys and a shiftable belt, in combination, a belt shifter comprising a movable member adapted to contact the belt, an arrow head cam mounted on said member, a plunger disposed in a socket provided on said frame, a spring in said socket for resiliently mounting said plunger, an arrow head cam formed on said plunger and adapted to cooperate with said first named cam to cause said belt shifter member to snap over from one position to the other at an intermediate point during the shifting movement.

'7. In a machine of the class described, in combination, a supporting frame, a grinding wheel mounted on said frame for combined rotary and reciprocating movement, means for controlling the movements of said wheel comprising a pulley operatively associated with said wheel and provided with two belt engaging surfaces of different diameters connected by a tapered surface, a countershaft on said frame adapted to be driven from a suitable source of power, a pulley on said countershaft, a belt trained around said last named pulley and adapted to engage either of said belt engaging surfaces on said first named pulley, a belt shifter for moving said belt from one of said surfaces to the other to effect a variation in the movement of the grinding wheel, resilient means associated with said belt shifter for retaining it in either of its shifted positions and for giving the belt a sudden and positive impetus toward said positions at a point during the shifting movement, an idler pulley contacting said belt and adjustably carried by said frame, a weighted lever arm pivoted to said frame, and a pulley carried by said arm and adapted to take up the slack in said belt resulting from shifting it to the surface of smaller diameter on the first named pulley.

8. In an abrading device of the class described, in combination, a supporting frame including a pair of side frames, a grinding wheel rotatably carried by said supporting frame, a dust collecting box disposed between said side frames and beneath said wheel, and a plurality of baffle plates extending transversely across said box, disposed threaded to said internal shaft, whereby the relative speeds of said shafts determine the direction of reciprocation of said wheel, a set screw threaded axially through the hub of said wheel and engaging said spline member for securing the latter in its operative position and adjusting its contact with said threaded shaft, and means for driving said hollow shaft and said threaded shaft at different relative speeds.

GIBSON H. KENNEDY. 

